Overmoulded reinforced metal/plastic composite front panel for motor vehicle

ABSTRACT

The invention concerns a front panel comprising a top metal section extending over the whole width of the panel and provided with means for fixing it to the motor vehicle structural elements, and at least a central jamb including means to be fixed to a hood lock and a cowl-beam of the vehicle. The section and the jamb are mechanically interlocked to form a single-unit assembly, said assembly being overmoulded with a plastic element of the front panel.

[0001] The present invention relates to a metal/plastic composite frontpanel for a motor vehicle.

[0002] Such a panel is a structural element of the vehicle which iscapable of incorporating various items of equipment of the vehicle, suchas headlamps, direction indicators, horn, heat exchanger, electric fanunit or entire cooling module, etc.

[0003] The front panel, provided in this manner with these items ofequipment, forms a single-unit assembly prepared and delivered by theequipment supplier, which is ready to be mounted on the vehicle by themanufacturer.

[0004] The mounting of this module is performed by connection to lateralstructural elements of the vehicle, such as side members, wings orbody-frame, then positioning a bumper or front shield mounted on themodule.

[0005] As a panel structure which is made entirely of plastic materialdoes not enable the safety requirements of the crash tests to becomplied with, for the structure of the front panel it is necessary tocombine elements made of plastic material (for lightness and lowmanufacturing cost) and metal elements (for mechanical strength). Themethod that is currently used consists of producing a section from adeep-drawn sheet and mounting it onto a plastic support by screwing orrivetting fixing sleeves.

[0006] In addition to this section, the panel comprises a central metaljamb comprising at its lower end a hole for fixing it to the beam of theshield or of the bumper of the vehicle. At its other end, the jamb isprovided with a system for fixing it to the bonnet lock of the vehicle.The jamb thus ensures, with the bonnet closed, the mechanical connectionbetween bonnet and shield to contribute to the overall rigidification ofthe structure of the vehicle.

[0007] The mounting of this jamb is usually performed by screwingtogether the bonnet lock and the jamb, with the interposition of a partof the panel, so as to interlock these three elements.

[0008] However, in this configuration, the connection between the paneland the jamb remains dismountable, so that a user of the vehicle may,for example after adjusting the lock, forget to reset all its fixingpoints, thus reducing the strength of the vehicle in the event of anaccident.

[0009] One of the objects of the present invention is to remove thisdrawback, by proposing a front panel structure incorporating the centraljamb which guarantees the overall mechanical strength and dispenses withdismountable assemblies.

[0010] The front panel of the invention is a composite panel of theknown type, comprising a top metal section extending over the wholewidth of the panel and provided with means for fixing it to structuralelements of the vehicle, as well as at least a central jamb comprisingmeans for fixing to a bonnet lock, on the one hand, and a shield beam ofthe vehicle, on the other hand.

[0011] According to the invention, the section and the jamb aremechanically interlocked to form a single-unit assembly, said assemblybeing overmoulded with a element made plastic material of the panel.

[0012] The element made of plastic material advantageously comprisesvertical ribs for strengthening the section.

[0013] The section and the jamb may be joined before overmoudling theplastic element, in particular by clinching, welding or rivetting, or inaddition during the overmoulding process, in particular by clinching.

[0014] Other characteristics and advantages of the invention will becomeapparent from the detailed description of an exemplified embodimentbelow, given with reference to the attached drawings.

[0015]FIG. 1 represents in a front perspective view, the metal part ofthe front panel according to the invention, before overmoulding theplastic material.

[0016]FIG. 2 represents, also in a front perspective view, the finishedpanel, after overmoulding the plastic material.

[0017]FIG. 3 represents in a rear perspective view one of the lateralends of the panel of FIG. 2, illustrating in particular the penetrationbetween the metal element and the plastic material.

[0018]FIG. 1 shows the metal element 10 of a metal/plastic compositepanel according to the invention. The metal element comprises atransverse section 12 provided at its ends with holes 14 for fixing toside members or to wings of the vehicle, so as to guarantee themechanical strength of the frame of the latter. This section may beproduced, for example, by punching and deep-drawing a sheet to thedesired shape.

[0019] The element 10 also comprises a central jamb 15 comprising at itslower free end a hole 16 for fixing it to the beam of the shield or ofthe bumper of the vehicle. At its other end, the jamb 15 is fixed in anon-detachable manner at 18 to the section 12. This fixing may beachieved by various known methods, for example by welding, rivetting orclinching (plastic deformation of one of the parts so as to fill byplanishing a matching dovetail-shaped blank of the other part).

[0020] The metal part 10 produced in this manner is then overmoulded bya plastic material, to obtain the front support illustrated in FIGS. 2and 3.

[0021] For this overmoulding, one may use, for example, the method forproducing a metal/plastic composite element disclosed in EP-A-0 370 342:reference can be made to this document for further details on theassembly of the overmoulding and the materials that can be used for thispurpose, in particular a thermosetting or thermoplastic syntheticmaterial such as a glass-fibre reinforced polyamide (of course thischoice is in no way restrictive) moulded by injection under pressure.

[0022] The overmoulded element comprises a longitudinal portion 20 thatcomes to surround the metal element 10. It comprises, in a manner knownper se, structural parts such as 22 for fixing to the beam of the shieldbesides the fixing to point 16 of the jamb 15, or in addition such as24, which are able to receive headlamp units, or in addition a seat 26for a bonnet lock integral with the metal element 10.

[0023] The plastic structure also comprises a system of ribs such as 28which enables the rigidity of the section 12 to be increased. Similarly,the jamb 15 may comprise a system of ribs enabling its rigidity to beincreased.

[0024] It will be noted, as illustrated, that the metal element 10 isonly partially embedded in the plastic material so as to leave certainparts of the section or of the jamb projecting, in particular thosecomprising holes for connection to other members of the vehicle.

[0025] Thus a panel is obtained that comprises a non-dismountable,integrated central jamb 15, that enables the drawbacks of mounted jambsof the panel structures that have been proposed until now to be removed.

[0026] Various refinements of this structure may of course be consideredwithout departing from the scope of the invention.

[0027] Thus, the section 12 may be produced in one or two parts, as afunction of the design choices for the vehicle. Moreover, the connectionbetween the jamb 15 and the section 12 may be performed beforeovermoulding as well as during overmoulding (for example by clinching tothe interior of the overmoulding mould, then injection of the plasticmaterial).

[0028] With respect to the fixing of the bonnet lock, it can beperformed on one of the elements, section 12 or jamb 15, or on both atthe same time.

[0029] Of course, in addition to the central jamb 15, other supportelements can be integrated in the panel according to the same principle,for example by lateral fastening lugs, additional jambs, etc., here toothe metal parts all being joined to one another then overmoulded to forma non-demountable unit.

1. A metal/plastic composite front panel for a motor vehicle, comprisinga top metal section (12) extending over the whole width of the panel andprovided with means (14) for fixing it to structural elements of thevehicle, as well as at least a central jamb (15) comprising means (16)for fixing to a bonnet lock, on the one hand, and a shield beam of thevehicle, on the other hand, which panel is characterised in that thesection and the jamb are mechanically interlocked to form a single-unitassembly, said assembly being overmoulded with an element (20) made ofplastic material of the panel.
 2. A panel according to claim 1,characterized in that the element (20) made of plastic materialcomprises vertical ribs (28) for strengthening the section.
 3. A panelaccording to one of claims 1 and 2, characterised in that the section(12) and the jamb (15) are joined before overmoulding the plasticelement, in particular by clinching, welding or rivetting.
 4. A panelaccording to one of claims 1 and 2, characterised in that the section(12) and the jamb (15) are joined during the overmoulding of the plasticelement, especially by clinching.